Rewards• One-minute help• Twenty-minutes help• Translation help• List of gold, silver, bronze, iron and colour sponsors


cover Thank you for your help! We will reward it. The reward will increase with your effort and with the effect it has on the quality of the book series.


One-minute help

You can help this project in several ways:

To do more, read on.


Twenty-minutes help – and prizes

The following contributions would be particularly welcome, and we offer prizes for them:

If you can help on any of these topics or you think some issue not included in the text should be added, email me at; I'll consider it for the next edition. All help is welcome.


Translation help

Many readers want translations. If you want to help in translating parts of the text into your language, read about details on how to do it below and then let me know. You will have many readers. Because our non-profit has no funds to pay for translations in advance, we will organize royalties for the translator in each paper book sale.

Translating is fun. A chapter or two are completely sufficient and are very welcome! You do not need to translate a whole volume. And you will learn about physics while doing so. In exchange, I will explain everything that is unclear. But translation is also work - even if Google Translate is used as helping tool. If you have the time for translating, please get in touch. In exchange, I will help you and motivate you wherever I can.

You will get recognition. Your name will be (since 2017) on the external title page (if you translated the whole volume) and on the internal title pages of the text, and of course I will thank you in the text and on the website for your help. And if you have suggestions for improvement, I will do what I can to add them into the text.

Procedure and conditions: To keep the text free for all and of high quality at the same time, a translation requires that you agree to the following conditions and procedure (made simpler in 2019):


Gold sponsors

Silver sponsors

Bronze sponsors

Iron sponsors

The SchoolTutoring Academy provided a donation in support of better physics education.
Donations were also provided by Robrecht De Rouck, Virginia Lira and Liliana Alonso and a number of other donors who prefer to be unnamed.

Content: Numerous readers have provided material for this text: a warm thank-you to every one of them. Important material was provided by Bert Peeters, Anna Wierzbicka, William Beaty, Jim Carr, John Merrit, John Baez, Frank DiFilippo, Jonathan Scott, Jon Thaler, Luca Bombelli, Douglas Singleton, George McQuarry, Tilman Hausherr, Brian Oberquell, Peer Zalm, Martin van der Mark, Vladimir Surdin, Julia Simon, Antonio Fermani, Don Page, Stephen Haley, Peter Mayr, Allan Hayes, Igor Ivanov, Doug Renselle, Wim de Muynck, Steve Carlip, Tom Bruce, Ryan Budney, Gary Ruben, Chris Hillman, Olivier Glassey, Jochen Greiner, squark, Martin Hardcastle, Mark Biggar, Pavel Kuzin, Douglas Brebner, Luciano Lombardi, Franco Bagnoli, Lukas Fabian Moser, Dejan Corovic, Steve Carlip, Corrado Massa, Tom Helmond, Gary Gibbons, Heinrich Neumaier, Peter Brown, Paul Vannoni, John Haber, Saverio Pascazio, Klaus Finkenzeller, Leo Volin, Jeff Aronson, Roggie Boone, Lawrence Tuppen, Quentin David Jones, Arnaldo Uguzzoni, Frans van Nieuwpoort, Alan Mahoney, Britta Schiller, Petr Danecek, Ingo Thies, Vitaliy Solomatin, Carl Offner, Nuno Proença, Elena Colazingari, Paula Henderson, Daniel Darre, Wolfgang Rankl, John Heumann, Joseph Kiss, Martha Weiss, Antonio González, Antonio Martos, John Heumann, André Slabber, Ferdinand Bautista, Zoltán Gácsi, Pat Furrie, Michael Reppisch, Enrico Pasi, Thomas Köppe, Martin Rivas, Herman Beeksma, Tom Helmond, John Brandes, Vlad Tarko, Nadia Murillo, Ciprian Dobra, Romano Perini, Harald van Lintel, Andrea Conti, François Belfort, Dirk Van de Moortel, Heinrich Neumaier, Jaroslaw Królikowski, John Dahlman, Fathi Namouni, Paul Townsend, Sergei Emelin, Freeman Dyson, S.R.Madhu Rao, David Parks, Jürgen Janek, Daniel Huber, Alfons Buchmann, William Purves, Pietro Redondi, Sergei Kopeikin, Helmut Wunderling, Frank Sweetser, Farooq Ahmad Bhat, plus a number of people who chose to remain unnamed.

Animations and films: All included films are copyrighted; they were kindly provided by Martin Elsässer, Jarmo Hietarinta, Lim Tee Tai, Thomas Weiland, Daniel Schroeder, Roger Sabbadini, Dean Dauger, Greg Egan, Jake Socha, Lucas Barbosa, José Antonio Díaz Navas and Ute Kraus.

Photographs: Almost all photographs, in total more than 200, shown in the text and on the website are copyrighted; permission to use them has been kindly provided by each copyright holder. The names are mentioned below each picture, in the index of names, and on the picture credit page in the appendix.

Software: The textbook was typeset using its own LaTeX class file, the MinionPro package and over 60 existing LaTeX packages, using Gerben Wierda's gwtex distribution and Andrew Trevorrow's OzTeX. Numerous limitations and bugs in the tex distribution, in LaTeX, in LaTeX packages, in programming editors, and even in Adobe Acrobat had to be corrected to typeset the text. The software tools were refined with the repeated and valuable support of Donald Arseneau; help came also from Ulrike Fischer, Piet van Oostrum, Gerben Wierda, Klaus Böhncke, Craig Upright, Herbert Voss, Andrew Trevorrow, Danie Els, Sebastian Rahtz, Don Story, Vincent Darley, Johan Linde, Joseph Hertzlinger, Rick Zaccone, John Warkentin, Ulrich Diez, Uwe Siart, Will Robertson, Joseph Wright, Enrico Gregorio, Rolf Niepraschk, Alexander Grahn and Michael Zedler. The beautiful Minion math fonts are those of Johannes Küster; they are found at Typoma.

Website: The programming of the html pages owes much to the help of Greg Smith and Michael Beretka. Chris Garbers helped for the wiki and many other issues. Ipad tests are due to Rick Shoal. The website uses several PHP scripts from the PHPJunkyard and from Phil Connell. Translations of the html pages are due to Daniel Gutmanas, Romano Perini, Matous Ringel, Marek Gajdos, Irwan Prasetya Gunawan, Jarosław Królikowski, Johnny Chadda, Martin Clausen, Dimitar Genchev, Ryan, Kasper Olsen, Helga Trapp, Thomas Wahlstrøm, Gorka Ochoa, Ambrož Demšar, Roman Beslik, Paul Townsend, Kristjan Kannike, Hirooka Megumi, Mahdi Samadzad, Rahele Mashhadiebrahim, Kishan Kumar, Ahmed Bassel Radwan and Dragos Vulovic.

Hardware: Without the excellent and professional service of Gravis in Munich this project could not have been realized.

Colour sponsors

The many readers who sent feedback, suggestions and criticism helped making this text into what it is today. Thank you for the support! You add the colour to this project.



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